Device for automatically winding up a feeder cable

Claim 1

Apparatus for automatically winding up an electrical cable on a drum by means of a coil spring stressed with the unwinding of the cable, said drum having a hallow hub, the drum being journalled with its hollow hub in two sleeve bearings of different diameters formed on a pivot spindle fixed on a base plate, two sliding contact elements comprised of contact rings and contact springs being arranged between said bearings, the contact rings of said elements being arranged non-rotatably on the pivot spindle and the contact springs being arranged on a contact carrier insertable in a recess of the hub, characterized through the features (a) an opening of the hollow drum hub (3.1) facing the base plate (1) is provided with a collar (3.11), (b) an outer drum flange (3.3) froms a central hollow space (3.4) for receiving a coil spring (6), (c) a middle part of the hub (3.1) contains said recess (3.12) for the contact carrier (12) for said contact springs (13,21) and a pull relief (13.13) for the electrical cable (9), (d) locking pawls (1.2) are formed in the base plate and engage the collar (3.11) of the hub (3.1) thereby to protect the drum (3) against axial drawing off from the pivot spindle (2), (e) the pivot spindle (2) is formed hollow in a hub area, is formed solid in an end area and is provided with at least one slit (2.12) in said solid end area, (f) the coil spring (6) is formed as a spiral spring with hook formed ends (6.1, 6.2) of which an inner hook end (6.2) is inserted in the slit (2.12) in the end area of the pivot spindle and an outer hook end (6.1) is inserted in an opening (3.6) on the wall of the hollow space (3.4), (g) the contact carrier (12) is mounted in the recess (3.12) of the hub (3.1) so that the contact springs (13,21) engage the contact rings (10,20), and, (h) the contact springs (13,21) engage opposing sides of the contact rings (10,20) so that contact pressures are applied only in the contact elements.